1. Field of the Invention
The present invention relates to a cooling system in a small size air-cooled two-stroke cycle combustion engine for driving mainly a work machine such as, for example, a brush cutter.
2. Description of Related Art
An air cooled combustion engine such as, for example, a small size two-stroke cycle combustion engine generally makes use of a cooling fan, and a stream of cooling air induced by the cooling fan is introduced through a cooling passage, comprised of a fan covering and a cylinder covering (shroud) for covering side and top of an engine cylinder, to the engine cylinder so as to cool the engine cylinder. The cooling air then drawing heat from the engine cylinder is subsequently discharged to the atmosphere through the cylinder covering. In order to increase the cooling efficiency, the Japanese Patent No. 3729667 suggests the two-stroke cycle combustion engine of a type in which a metallic wind-blocking plate is fitted to a top surface of the engine cylinder and a baffle made of a resinous material and formed integrally so as to protrude downwardly from the cylinder covering so that the stream of cooling air can be efficiently guided towards the cylinder.
It has, however, been found that the above mentioned patent requires a gap or space to be defined between the resinous baffle and the metallic wind-blocking plate in order to prevent the elevated temperature of the cylinder from being transmitted to the resinous baffle and, therefore, the cooling air is apt to leak outwardly through this gap or space, accompanied by reduction in cooling effect.